<?php
/**
 *   加密工具类
 *
 * User: jiehua
 * Date: 16/3/30
 * Time: 下午3:25
 */
namespace Common\Lib\Alipay;

class AopEncrypt{
	/**
	 * 加密方法
	 * @param string $str
	 * @return string
	 */
	 public  static function encrypt($str,$screct_key){
		//AES, 128 模式加密数据 CBC
		$screct_key = base64_decode($screct_key);
		$str = trim($str);
		$str = addPKCS7Padding($str);
		$iv = mcrypt_create_iv(mcrypt_get_iv_size(MCRYPT_RIJNDAEL_128,MCRYPT_MODE_CBC),1);
		$encrypt_str =  mcrypt_encrypt(MCRYPT_RIJNDAEL_128, $screct_key, $str, MCRYPT_MODE_CBC);
		return base64_encode($encrypt_str);
	}

	/**
	 * 解密方法
	 * @param string $str
	 * @return string
	 */
	public static function decrypt($str,$screct_key){
		//AES, 128 模式加密数据 CBC
		$str = base64_decode($str);
		$screct_key = base64_decode($screct_key);
		$iv = mcrypt_create_iv(mcrypt_get_iv_size(MCRYPT_RIJNDAEL_128,MCRYPT_MODE_CBC),1);
		$encrypt_str =  mcrypt_decrypt(MCRYPT_RIJNDAEL_128, $screct_key, $str, MCRYPT_MODE_CBC);
		$encrypt_str = trim($encrypt_str);

		$encrypt_str = stripPKSC7Padding($encrypt_str);
		return $encrypt_str;

	}

	/**
	 * 填充算法
	 * @param string $source
	 * @return string
	 */
	function addPKCS7Padding($source){
		$source = trim($source);
		$block = mcrypt_get_block_size(MCRYPT_RIJNDAEL_128, MCRYPT_MODE_CBC);

		$pad = $block - (strlen($source) % $block);
		if ($pad <= $block) {
			$char = chr($pad);
			$source .= str_repeat($char, $pad);
		}
		return $source;
	}
	/**
	 * 移去填充算法
	 * @param string $source
	 * @return string
	 */
	function stripPKSC7Padding($source){
		$source = trim($source);
		$char = substr($source, -1);
		$num = ord($char);
		if($num==62)return $source;
		$source = substr($source,0,-$num);
		return $source;
	}

}